51% of emails are opened on mobile devices - don’t forget to check the mobile preview for your email! Keep your email subject line short and attention-grabbing. Let your imagination run wild. Generating witty text... One Mississippi, two Mississippi… Don’t make ‘em yawn! Keep your emails exciting and brief. Don’t forget to add a fun, relevant call-to-action button to your email. Boost your email opens with a punchy subject line.